Section 35(4) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(4)Indian Fleet Auxiliaries shall be punctilious in lowering their colours to foreign ships of war. They are not required to lower their colours to Indian Naval Ships but shall hoist their distinguishing pendants when entering an Indian Naval port, joining the fleet, or passing Indian Naval Ships at sea.Section IV - Salutes in General
